i2c: mediatek: Add OFFSET_EXT_CONF setting back

In the commit be5ce0e9 ("i2c: mediatek: Add i2c ac-timing adjust
support"), we miss setting OFFSET_EXT_CONF register if
i2c->dev_comp->timing_adjust is false, now add it back.

Fixes: be5ce0e9 ("i2c: mediatek: Add i2c ac-timing adjust support")
Signed-off-by: Kewei Xu <kewei.xu@mediatek.com>
Reviewed-by: Qii Wang <qii.wang@mediatek.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

drivers/i2c/busses/i2c-mt65xx.c

@@ -41,6 +41,8 @@
 #define I2C_HANDSHAKE_RST		0x0020
 #define I2C_FIFO_ADDR_CLR		0x0001
 #define I2C_DELAY_LEN			0x0002
+#define I2C_ST_START_CON		0x8001
+#define I2C_FS_START_CON		0x1800
 #define I2C_TIME_CLR_VALUE		0x0000
 #define I2C_TIME_DEFAULT_VALUE		0x0003
 #define I2C_WRRD_TRANAC_VALUE		0x0002
@@ -480,6 +482,7 @@ static void mtk_i2c_init_hw(struct mtk_i2c *i2c)
 {
 	u16 control_reg;
 	u16 intr_stat_reg;
+	u16 ext_conf_val;
 
 	mtk_i2c_writew(i2c, I2C_CHN_CLR_FLAG, OFFSET_START);
 	intr_stat_reg = mtk_i2c_readw(i2c, OFFSET_INTR_STAT);
@@ -518,8 +521,13 @@ static void mtk_i2c_init_hw(struct mtk_i2c *i2c)
 	if (i2c->dev_comp->ltiming_adjust)
 		mtk_i2c_writew(i2c, i2c->ltiming_reg, OFFSET_LTIMING);
 
+	if (i2c->speed_hz <= I2C_MAX_STANDARD_MODE_FREQ)
+		ext_conf_val = I2C_ST_START_CON;
+	else
+		ext_conf_val = I2C_FS_START_CON;
+
 	if (i2c->dev_comp->timing_adjust) {
-		mtk_i2c_writew(i2c, i2c->ac_timing.ext, OFFSET_EXT_CONF);
+		ext_conf_val = i2c->ac_timing.ext;
 		mtk_i2c_writew(i2c, i2c->ac_timing.inter_clk_div,
 			       OFFSET_CLOCK_DIV);
 		mtk_i2c_writew(i2c, I2C_SCL_MIS_COMP_VALUE,
@@ -544,6 +552,7 @@ static void mtk_i2c_init_hw(struct mtk_i2c *i2c)
 				       OFFSET_HS_STA_STO_AC_TIMING);
 		}
 	}
+	mtk_i2c_writew(i2c, ext_conf_val, OFFSET_EXT_CONF);
 
 	/* If use i2c pin from PMIC mt6397 side, need set PATH_DIR first */
 	if (i2c->have_pmic)